Breaking device for hollow cylinders



W. S. PIERCE. JR

BREAKING DEVICE FOR HOLLOW CYLINDERS May 31, 1927. 1,630,759

Filed April '23. 1926 INVENTQR v Winslow 61 I 'ceJ/t 9 5 7 BY ATTORNEYS I May 31, 1927.

STATES. PATENT Gi l iltin wins-Low s. PIERCE, JR, OFBAYVILLE, new YORK.

BREAKING DEVICE FOR HOLLOW CYLINDERS.

Application filed April 23,

1 bearing races of the type disclosed in the above mentioned application and paten-hl prefer to apply force to the inner surface of "he cylinder until sufficient tensile stress is developed in the cylinder walls to break the cylinder along axial lines previously l. .l or grooved This force is applied to the inner s rface of the cylinder throughout substan 'lly the entire area of the surface. .lt may be done by subjecting the cylinder to the action of fluid pressure, or by filling the cylinder with a soft metal, such as lead, and applying suflicient pressure to t-i118 metal to break the cylinder. Furthermore, an expansion device comprising two members each having one plane surface and one senricvlindrical surface closely fitting the tlr, of the cylinder, may be employed. A ii member, wedge-shaped, engages with llitt plane surface of each of the other membin .5 to force them apart until the cylinder is lr ken.

l have found when using such a device in practice that at times there is a tendency for one side of the cylinder to break before the oil .1 with the result that a hinging aclion ta. 3 place about the side last to break. lhis leads to a distortion of the line of fracture and sometimes a damaging of the broken surface itself. The importance of such a condition is particularly emphasized for such cases where the cylinder or hearing completely machined before fracturiug. i iny slight distortion or feathering of thcfracture then becomes extremely undesirable.

in order to avoid the various above mentioned di'liicultics, l have constructed a breaking device having an external yoke, partially surroundingthe cylii'ider, to produce straight line separation of the broken tionsthereof. Any tendency for a hinging action thus el minated. In general, a i be accomplished by a pair of spring 1926. Serial N0. 104,110.

each side of the intended plane of fracture and so shaped as to contact with the outside surface of the cylinder along substantially a semi-cylindrical surface.

To still further assure smooth fracture, I have devised as a particular form of my invent-ion an internal expansion member providing an even distribution of the expansion force of the wedge. I obtain this result by longitudinally machining the inner surface of the cylinder and the two semicylindrical surfaces of the members 0011- tacting therewith, to form ribs and grooves. 1 thereby produce a positive non-rotative contact between the internal expansion member and the inner surface of the cylinder that gives an even distribution of the cxpansion force of the wedge throughout the cylinder walls.

My invention can be best understood by considering the following detailed description, which is to be taken in conjunction with the accompanying drawings wherein:

Figure 1 is a perspective view of a hearing cylinder in the manufacture of which this invention may be used;

Figure 2 is a cross section of the bearing cylinder of Figure 1 showing the internal and external scorings'or grooves along which the cylinder fractures upon breaking;

Figure 3 is an elevation showing a bearing cylinder placed over an internal expansion member;

Figure l is an elevation showing one form of a complete breaking device;

F igure is a section through Figure 4: on the line 5 5;

Figure 6 is an elevation of another form of a complete breaking device;

Figure 7 is a section through Figure 6 on the line 7- 7. y

In describingthe invention more in detail in connection with the accompanying drawings, and the embodiment of the invention illustrated therein, it will be understood that the drawings as well as the description are v intended to be illustrative of the invention,

and not to be limited to use in the manu facture of the particular type of hearing I have illustrated therein.

Figures 1 and 2 illustrate the type of bearing cylinders described in my previously mentioned application and patent. The scorings along which the cylinder breaks are clearly shown in Figure 2. It is this type of bearing cylinder that is shown in the drawings and that is described in the description as constituting one use for the breaking device of this application.

Figure 3 shows a form of theinternal expansion member with a bearing cylinder in position for breaking without the use out the external compression shoes. The hearing cylinder indicated at 1, and the two members having external, semi-cylindrical surfaces contacting with the inner surface of the cylinder are shown at 2-2. Each of these members may be provided wit-ha base portion 4t forming a support for holding the member in an upright position. The inner surfaces of the members are inclined to the axis of the cylinder, and a wedge 3 inserted between them as shown. The grooves along which the cylinder is to be broken should preferably be as nearly as possible in line with the longitudinal plane of the wedge, Such a position leads to a more even distribution of the expansion force of the wedge,

with the resultthat a more unitorm tensile stressis developed across both lines of tracture. i a I Ifthe cylinderwere, broken with the device as shown inFigure 3, all of the troubles and difliculties in obtaining a smooth clean fracture as outlined in the earlier discussion would be present. The illustration makes clear the hinging action that can take place if one side shouldbreak before the other, and. also the lack of any icons to prevent it should it occur. i

By placing a set of external restricting or compression shoes partially surrounding the cylinder, as shown in Figure 4, the possibility of such hinging action is eliminated. The external member can he slipped over the assembly of Figure 3, and adjusted to the position shown. The two parallelopipedal shoes 5, 5 are interconnected by bolts (5 and compressed together under the action of coil springs 7. The bolts have fixed heads 9 and adjustable nuts 8 to permit regulation of the degree of spring compression. I have illustrated four bolts, each having a coil spring, but it is conceivable that 6 and perhaps more could be used and that some other form of spring loading could be adapted. In practice, however I have found four bolts with a coil spring on each bolt to be very satisfactory. Alignment splines might also be provided.

The advantage oi such a set of shoes (le pends upon the restraining action they offer to any force other than that which is parallel to the line of the bolts. Figure 5 perhaps makes such condition a little clearer and also illustrates to better advantage the contact between the cylinder and the various members oi the breaking device. In this figure the wedge is indicated at 8 and. the internal expansion members contacting; with the inner surface of the cylinder at Q, 2.

of the shoes contacts with the outer surface oi the cylinder. The bolts and springs are as previous-fly d 'crihed.

With the cylinder in the position slmwu, which lu-iucis the scored seetioiu: midway between the two shoes and subshuuially in line with the wedge, the wcdu e 2, is graduah ly forced between the members 2, :2 and a. tensile stress developed across the scored section of the cylinder. If this stress be comes great enough the cylinder wall will break at that point. As the ox iuinsiou grad ually increases the shoes 5, will slide laterally along the bolts 6 against the action oi the springs T the amount depending; upon the material of which the cylinder is made. it all times there is a constant conipi force being alerted upon the outer surface of the cylinder tending to restrain any great outward movement. Since the shoes fit snugly over the bolts they are tree to move in but one di.recti n1tl1at along the line 01' the bolts. Even if one side breaks betorethe other no hinging' action about the line to break can result betaiuse such a rotative force applied to one side of the shoe would immediately produce a binding action that would lock the shoes against further movement. The closer the shoes lit the bolts the more instantaneous will such action be, and the more etleetive the restraining action of the shoes. From this it is evident that the shoes. hold the two halves of the eylirulers together in their original relation until both scorings have broken and the tl'orce of expansion has once more become a straight line force parallel to the line of the bolts. ll both sides break siuuiltaiuzously no bindinp action will occur, and theshoes will scpa ate under the straight line force (it erqiansiou. It the mass of the shoes is made very large compared with the cylinder the restrictive force becomes still greater due. to theadded force needed to set such large masses in motion.

To make a clean even break doubly sure I may combine the same external shoes with a somewhat dili'erent form of internal expansion member, as shown in Figure (l and Figure 7. The tendency for one side to break before the other, which may occur with a smooth internal expansion member may be due to uneven distrilmtion of the expansion force of the wedge through the cylinder walls. A slight change in the position of the grooves away from the line oi. the wedge would be SlllllClOlll. to produce diilfereut ieih silo stress across the two scored sections,

granting, of course, that the cylinder is of uniform density throughout. rnother cause might be the lack of a positive non-rotatrve ill! lllll contact between the expansion member and the inner surface of the cylinder. Asthe cylinder expands under the force of the wedge the force distribution across the contact surface might change conside'ably in location if the expansion member isfree to move relatively to the cylinder.

By machining the semi-cylindrical surfaces of the internal expansion member and also the inner surface of the cylinder to form longitudinal ribs and grooves, as shown at 11, Figure 7, avpositive interlocking contact between the two is obtained. If the cylinder 1 is now placed over the internal expansion member 2', with the scoring in correct alignment with the wedge. it will be locked in that position until removed. Rotative movement orslipping of one about the other, is impossible. .T he result is that when the wedge .is driven down the expansion force will be transmitted through the interlocking ribs and grooves to every part of the cylinder wall. As the cylinder expands the internal member expands with it. always maintaining the same force distribution across the contact surface because of the positive engagement of the ribs and grooves. The tensile then developed across each scored sec tion will be of substantially the same magnitude. and both sides will break at the same time. p

I have found such a breaking device as set forth in the foregoing description and drawings to be verysatisfactory in use. By drivin the wed e between the two )arts of the internal expansion member force is applied to the inner surface of the cylinder in such a manner that there is no tendency to distort the two sections of the cylinder during the breaking operation. The semi-cylindrical surfaces of the members 2, 2 or 2, 2 fit exactlythe inner surface of the cylinder, and the concave portions of the two external shoes 5. 5 tit exactly the outer surface of the cylinder; the result is that the only stress of any great magnitude developed in the eyl= inder walls is a tensile stress across the scored sections. i

In the one form characterized by the device shown in Figure 4 any hinging action of the cylinder halves due to one side breaking before the other is entirely neutralized by the binding action of the external shoes, and a perfect break is assured. In the other form. illustrated in Figure 6, the ribbed and grooved contact surface of the internal memher so distributes the expansion force that the possibility of one side breaking first is eliminated. and the compressing action of the external shoes assures a quick. sharp and simu taneous break at both scored sections.

is to be understood that. yarious changes and modifications can be made in the em bodiment of my invention as illustrated and described without departing from the spirit ly surround the cylinder to be broken for and scope. of the invention as. defined by. the appended claims.

claim: LA breaking device for hollow cylinders comprisingan internal, expandingmember for applying forceto the inner, surface of the cylinder to break itintosections .and an external restricting member for restricting the movement of said sections.

2. A breaking device for hollow cylinders 7 comprising an internal expanding member. of a plurality of parts "for applying force to the, inner surface of the cylinder to break it into sections. and an external restricting member of. a plurality of parts for restrictQ so ingthe movement of said sections.

3. A breaking device for hollow cylinders comprising an external restrictingmember and an internal expandinglmember having two semi-cylindrical portions with radii s. substantially equal to the bore of the short cylinder to be broken. the said semi-cylindrical surfaces being adapted to, contact Wlt-ll. the inner surface of sald cylinder.

4:. A ln'eakiug device for hollow cylinders so con'iprising an external restricting member.

and an internal expanding member composed of three portions, two of which have one plane surface undone semi-cylindrical surface, the. semi-cyliiulrical surface having sub semi-cylindrical surfaces into contact with the bore of the cylinder'to be broken. I

A breaking device for hollow cylinders comprising an internal expandingmember 10 for applying force to the inner surface of the cylinder tobreak it into sections, and an external restricting member composed of two parallelopipedal shoes adapted to partrestricting the movement of said sections.

6. A breaking device for hollow cylinders comprising an internal expanding member for applying force to the inner surface of the cylinder. to break it into sections. and an 1 external restricting member composed of two parallclopip-edal shoes transversely yieldable for restricting the movement of said sections.

7 A breaking device for hollow cylinders 1.

comprising an internal expanding member for restricting 1? for applying force to the inner surface of the cylinderto break itinto sections, and an external, transversely yieldable, restricting member adapted to partially surround the cylinder to be broken for restricting the movement of said sections. a

9. k breaking-device for hollow cylinders comprising an internal expanding member, and an external, transversely yieidable, restricting member adapted to prevent rotation of at least a portion ofthe cylinder to be broken along any of its lines of fracture.

10. A breaking device for hollow cylinders comprising an internal expanding member for applying force to the inner surface of the cylinder to break it into sections, and an external restricting member composed of two spring-loaded parallelopipedal shoes each with aconcave inner surface of substantially the same radius as that of the outside surface of the cylinder to be broken for restricting the movement of said sec tions. a a

11. A breaking device for hollow cylinders comprising an internal expanding member for applying force to the inner surface of the cylinder to break it into sections, and an external restricting member composed of two spring-loaded parallelopipedal shoes having concave inner surfaces adapted to diametrically contact with the outside surface of the cylinder to be broken for restricting the movement of said sections.

12. A breaking device for hollow cylinders comprising an internal expanding member, and an external, transversely yieldable, restricting member composed of two parallelopipedal shoes having concave inner surfaces adapted to diametrically contact with the outside surface of the cylinder to be broken, and adapted to prevent rotation of at least a portion of said cylinder about any of its lines of fracture.

13. A breaking device for hollow cylinders comprising an internal expanding member, and an external, transversely yieldable, restricting member composed of two parallelopipedal shoes having inner faces adapted to be'diametrically opposed across the cylinder to be broken, andparallel to both a plane containing the longitudinal axis of the wedge of said internal expanding member and any diameter containing the lines of fracture of said cylinder.

14. A breaking device for hollow cylinders comprising an internal expanding member, and an external, restricting mem- Lil) ber composed of two shoes adapted to be diametrically opposed across the cylinder to be broken and limited to a line of'motion within or parallel to the plane containing the axis of said cylinder and the longitudinail axes of both shoes.

15. A breaking device for hollow cylinders comprising an external restricting member, and an internal expanding member having a multiplicity of axial ribs and grooves on its outer surface adapted for positive contact with the inner surface of its outer surface adapted to it intothe ribs and grooves on the inner surface of sand cylinder, whereby positive and non-rotative contact is obtained between said expanding member and said cylinder.

17. The method of breaking hollow cylinderswhich comprises scoring one surface of a hollow cylinder with a groove, scoring the other surface of the cylinder, placing around said cylinder a spring-loaded restricting member comprising two shoes diametrically contacting, between the scored grooves, with the outer surface of said cyl inder, and applying a force to the inner surface of the cylinder until said cylinder fractures along the scored grooves.

18. The method of breaking hollow cylinders which comprises scoring one surface of a hollow cylinder with a groove; scoring the other surface of the cylinder; placing said cylinder over a device comprising two members each with one semi-cylindrical surface having a radius substantially equal to that of the bore of said cylinder and a plane surface longitudinally inclined to the axis of said cylinder, and a third wedge-shamed memberadapted to urgesaid sc1nicylinc:lrical surfaces into contact with the inner sur face of said cylinder; placing around the said so mounted cylinder a springdoaded member comprising two shoes diametrically contacting, between the scored grooves, with the outer surface of the cylinder; and forcmg said wedge-shaped member between the adjacent members of said device until the cylinder fractures along the scored grooves.

19. The method of breaking hollow cylinders which comprises scoring one surface of a hollow cylinderwith a groove; scoring the other surface of the cylinder; broaching the inner surface of the cylinder to produce a multiplicitybf ribs and grooves; placing said cylinder over a device comprising two members similarly ribbed and grooved to lit the inner surface of the cylinder with positive, non-rotative contact, each of said members having one semi-cylindrical surface with a radius substantially equal to that of the bore of said cylinder and a plane sin-face longitudinally inclined to the axis of said cylinder, and a third wedge-shaped member adapted to urge said semi-cylindrical surfaces into contact with the inner surface of said cylinder; placing around the said niiounted cylinder a spring-loaded, transversely yieldable member adjusted to prevent rotation of any portion of said cylinder about any of its lines of fracture, and comprising two shoes diametrically contacting with the outer surface of the cylinder be tween the scored grooves; and forcing said wedgeshaped member between the adjacent members of said device until the cylinder fractures along the scored grooves.

20. The method of breaking hollow cylinders, which consists in scoring one surface of a cylindrical piece of metal with grooves having at least a portion thereof extending at an angle to any plane containing the axis of the cylinder, scoring the other face of the piece of metal, placing the piece of metal over a device comprising two semi-cylindrical pieces having radii substantially equal to that of the bore of the said piece of metal, the said semi-cylindrical surfaces being in contact with the inner surface of the said piece of metal, and forcing the two pieces of said device apart, while constantly maintaining the two portions of said piece of metal on opposite sides of said grooves in parallelism by a laterally yieldable pressure, until the piece of metal breaks along the scored grooves therein.

21. The method of breaking hollow cylinders, which consist-s in scoring one surface of a cylindrical piece of metal with grooves having at least a portion thereof extending at an angle to any plane containing the axis of the cylinder, scoring the other face of the piece of metal, placing the piece of metal over a device comprising members two of which each have one plane surface and one semi-cylindrical surface, the semi-cylindii cal surface having substantially the same radius as that of the bore of the said cylindrical piece of metal, and the plane surfaces being inclined at an angle to the axis of said cylindrical piece, the said third member be ing wedge-shaped and adapted to engage said plane surfaces so as to hold the semicylindrical surfaces in contact with the bore of said cylindrical piece of metal; and forcing said wedge-shaped member between the adjacent members of said device, while constantly maintaining the two portions of said piece of metal on opposite sides of said grooves in parallelism by a laterally yieldable pressure, until the lateral strain transmitted through said semi-cylindrical men1- bers to the said piece of metal causes the same to break along the scored grooves therein.

In testimony whereof I affix my signature.

wnNsLow s. PIERCE, JR. 

